Trencher attachment

ABSTRACT

The present disclosure provides a system and method of creating trenches of various widths, including widths that are substantially greater than the width of the boom head or even the chassis. According to the trencher system of the present disclosure, the boom is designed so that it can be easily configured to create a trench of a first width and subsequently create a trench of a second width that is different than the first width.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to provisional application No.61/047,052 filed Apr. 22, 2008, entitled Trencher Attachment, which isincorporated by reference in its entirety herein.

TECHNICAL FIELD

The present disclosure relates to trenchers and, more particularly, to awide boom attachment for a trencher.

BACKGROUND

Trenchers capable of digging/cutting trenches have a variety of uses.For example, in construction, trenchers are often used to dig trenchesfor laying pipes or cables. There exist a number of different types oftrenchers. One type of trencher includes a digger chain that rotates ona boom. The angle of the boom can be adjusted to control the depth ofthe cut. To cut the trench, the digger chain is rotated on the boomwhile the machine moves slowly in a direction away from the boom. Thewidth of the chain defines the width of the trench. In most trenchersthe width of the chain is limited by the width of the boom head andchassis. There exists some disclosures in the prior art relating tosystems and methods for creating a wider trench than is traditionallypossible. See, for example, U.S. Pat. No. 5,228,220 to Bryan, Jr. andU.S. Pat. No. 5,497,567 to Gilbert. However, there remains a need toprovide an improved system and method of creating wide trenches.

SUMMARY

The present disclosure provides a system and method of creating trenchesof various widths, including widths that are substantially greater thanthe width of the boom head and chassis width. According to the trenchersystem of the present disclosure, the boom is designed so that it can beeasily configured to create a trench of a first width and subsequentlycreate a trench of a second width that is different than the firstwidth.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a perspective view of a trencher according to the presentdisclosure;

FIG. 2 is a side view of the trencher of FIG. 1;

FIG. 3 is a front view of the trencher of FIG. 1;

FIG. 4 is a top view of an embodiment of cutting teeth and dirt drags ona chain assembly according to the present disclosure;

FIG. 5 is an end view of the embodiment shown in FIG. 4;

FIG. 6 is a front view of the trencher of FIG. 1 with the digger chainsremoved to show the main boom and auxiliary booms;

FIG. 7 is a top view of the trencher of FIG. 1 with the digger chainsremoved to show the main boom and auxiliary booms;

FIG. 8 is a top view of the main boom and auxiliary booms attached tothe chassis of the trencher of FIG. 1;

FIG. 9 is a perspective view of a distal end of the main boom with oneauxiliary boom removed;

FIG. 10 is a perspective view of the auxiliary boom of FIG. 1;

FIG. 11 is a perspective cross-sectional view of the auxiliary boomdrive shaft;

FIG. 12 is a perspective view of a portion of the auxiliary boom showinga tension system on the auxiliary boom; and

FIG. 13 is a side cross-sectional view of a portion of the auxiliaryboom shown in FIG. 12.

DETAILED DESCRIPTION

Referring to FIG. 1, a trencher according to the present disclosure isdescribed. The trencher 10 includes a chassis 12 that includes a firstend 14, a second end 16, a first side 22, and a second side 24. Thechassis 12 is supported on a pair of tracks 18, 20 located at each side22, 24 of the chassis. The chassis 12 is configured to support, amongother things, an operator cab 26, engine 28, hydraulic motors 30, and aconveyor system 32. In the depicted embodiments the engine 28 is used topower hydraulic motors 30 that drive the tracks 18, 20, the conveyorsystem 32, as well as other trencher operations (e.g., boom position anddigger chain rotation).

In the depicted embodiment, a main boom 34 is attached to the second end16 of the chassis 12. The main boom 34 includes a proximal end 36 (theend near the chassis 12) and a distal end 38 (the end far from thechassis 12). The main boom 34 supports a main digger chain 40, and ateach side of the main boom 34 are auxiliary booms 42, 44 that supportauxiliary digger chains 46, 48. In the depicted embodiment, the firstauxiliary digger chain 46 and the second auxiliary digger chain 48 areboth driven by the drive shaft assembly 50, and the drive shaft assembly50 is driven by the main digger chain 40. In use the main boom 34 islowered into the ground surface while the digger chains 40, 46, 48 aretypically rotating in a direction that cause the cut debris (dirt,stone, etc.) to be pulled into the trencher 10 and out via the conveyorsystem 32. Once the main boom 34 is lowered to the desired depth, thetrencher is driven slowly in a forward direction such that the first end14 is the front of the chassis 12 and the second end 16 is the rear ofthe chassis. This movement of the trencher 10 while the digger chains40, 46, 48 are rotating creates a trench in the ground that generallymatches the combined width of the digger chains 40, 46, 48.

Most prior art trenching systems do not include auxiliary booms andauxiliary digger chains. The width of the trench is typically limited bythe maximum width of the main digger chain. In turn, the maximum widthof the main digger chain is typically limited by the width of the boomhead and chassis. The present disclosure provides systems and methodsthat overcome the above-identified trench width limitations.

One embodiment of the present disclosure provides a kit that can be usedwith an existing trencher to enable it to create much wider trenches.The kit includes auxiliary boom(s), auxiliary digger chain(s), and anassociated drive shaft system. Another embodiment of the presentdisclosure provides digger chains with cutting elements thereon thatchannel the debris from the auxiliary digger chains into the path of themain digger chain to enable the main digger chain to feed the debrisinto the conveyor system. Another embodiment of the present disclosureprovides a trencher with a main boom as well as auxiliary booms, whereinthe auxiliary booms are configured to automatically funnel the debrisinto the path of a main digger chain so that the debris can beefficiently and effectively removed from the trench. In yet anotherembodiment a method of creating trenches of varying width is disclosedwherein auxiliary digger chains can be relatively quickly and easilyconnected to or removed from the trencher.

Referring to FIGS. 2, 6, 8 and 10, the auxiliary booms 42, 44 aredescribed in greater detail. In the depicted embodiment the auxiliarybooms 42, 44 include proximal ends 52, 53 and distal ends 54, 55. Theproximal ends 52, 53 of the auxiliary booms 42, 44 are the ends of thebooms that are closest to the chassis 12, and the distal ends 54, 55 ofthe auxiliary booms 42, 44 are the ends of the booms that are farthestfrom the chassis 12. In the depicted embodiment the auxiliary booms 42,44 include upper support surfaces 56, 57 and lower support surfaces 58,59. The upper support surfaces 56, 57 are the surfaces that support theauxiliary digger chains 46, 48 as they rotate over the top of theauxiliary booms 42, 44. The portion of the digger chains that aregenerally viewable in use (face upward) is referred to herein as theupper cut surface of the digger chains 46, 48. Therefore, the uppersupport surfaces 56, 57 support the upper cut surfaces 60, 61 of thedigger chains. The lower support surfaces 58, 59 are the surfaces thatsupport the lower cut surfaces 64, 65 of the auxiliary digger chains 46,48 as the digger chains rotate over the face of the auxiliary supportbooms 42, 44 that face the ground in use. The upper and lower supportsurfaces 56-59 are generally hidden under the digger chains 46, 48 whenthe digger chains are installed on the auxiliary booms 42, 44.

In the depicted embodiment the auxiliary booms 42, 44 include an idlergear 62, 63 positioned at the proximal ends 52, 53. The idler gear 62,63 of each of the auxiliary booms 42, 44 facilitates the movement of thetrack around the booms. In the depicted embodiment, the idler gear has asmaller diameter than the distance between the upper support surface 56,57 and the lower support surface 58, 59 (i.e., the thickness or depth ofthe booms 42, 44). In one embodiment the idler gear 62, 63 is positionedsuch that the pivot axis of the idler gear is above the center linebetween the upper and lower support surfaces 56-59 of the auxiliarybooms (FIG. 2). This configuration results in the lower cut surface 64(FIG. 1) gradually retracting from the lower cut surface of the maindigger chain 40. In the depicted embodiment the proximal ends 52, 53 ofthe lower support surface 58, 59 are curved such that the auxiliarydigger chains 46, 48 gradually pull away from the plane of the lower cutsurface of the main digger chain 40. In the depicted embodiment theradius of curvature of the curve of the lower support surface 58, 59 ofthe auxiliary boom 42, 44 is greater than the thickness of the auxiliarybooms 42, 44. This configuration facilitates the movement of debris cutby the auxiliary booms 42, 44 into the path of the main digger chain 40.

In one embodiment the idler gear 62, 63 is positioned such that theupper cut surfaces 60, 61 of the auxiliary digger chains 46, 48 aregenerally in the same plane (i.e., parallel) to the upper cut surface 64of the main digger chain 40. It should be appreciated that many otherconfigurations are also possible. For example, the axis of the idlergear could be positioned so that the upper cut surface 60, 61 at theproximal ends 52, 53 of the digger chains 46, 48 extend above the uppercut surface 64 of the main digger chain 40.

In the depicted embodiment the auxiliary booms 42, 44 include a modularconfiguration. The auxiliary booms 42, 44 each include three mainsections including a first end section that supports the idler gear 62,63 located at the proximal end 52, 53, a second section at the distalend that is shaped to receive a portion of the drive shaft assembly 50,and a third section positioned between the first section and the secondsection. In the depicted embodiment the second section includes a curvedend portion that is configured to allow the upper and lower supportsurfaces 56-59 of the auxiliary booms 42, 44 to transition smoothly withthe drive gears of the drive shaft assembly 50. In the depictedembodiment the third section can be removed and replaced with adifferent third section to adjust the length of the auxiliary boom 42,44. Alternatively, additional sections can be added between the firstand second section to increase the length of the boom without removingthe third section. Alternative embodiments of the modular feature of theboom may be configured such that the first and second section attachdirectly to each other without a mid-section therebetween. It shouldalso be appreciated that in some alternative embodiments, the auxiliarybooms may not be modular. In other words, they may be of a fixed lengththat is not adjustable.

Referring to FIGS. 3-5, the digger chains 40, 46, 48 are described ingreater detail. In the depicted embodiment the digger chains are shownas a series of linked together plates 100 with cutting elements 102 anddirt drags 104 attached thereto. The configuration and arrangement ofthe cutting elements facilitate the transport of the debris from thepath of the auxiliary digger chains 46, 48 into the path of the maindigger chain 40.

In the depicted embodiment the cutting teeth 102 are configured andarranged on the auxiliary digger chains 46, 48 in a pattern that directsthe debris cut by the auxiliary digger chains 46, 48 into the path ofthe main digger chain 40. FIG. 4 illustrates an embodiment of a patternof teeth 102 and dirt drags 104 that direct cut debris into the path ofthe main digger chain 40. The dirt drags 104 are angle towards the maindigger chain. Some of the dirt drags include a bent therein that thatfurther funnels the debris towards the main digger chain, others arestraight. The main digger chain 40 includes two rows of teeth that cometogether at the center of the digger chain. Between the teeth are largerdirt drags 106 that pull debris into the inlet of the conveyor system32. In the depicted orientation the teeth in the two rows come togetherat the proximal end 36 of the boom 34 and are spread apart at the distalend 38 of the boom 34. Referring to FIG. 5, the teeth are arranged sothat they are spaced apart along the cut surface of the digger chains.In the depicted embodiment, the spacing between the tips of adjacentteeth is between 1 to 2 inches. The spacing between the teeth on any oneplate may be much greater (e.g., 10 inches).

Referring to FIGS. 6-9 and 11, the drive shaft arrangement 50 isdescribed in greater detail. In the depicted embodiment, the drive shaftarrangement 50 includes a bearing assembly 70 that is configured toattach to the distal end 38 of the main boom 34 and rotatably support acylindrical shaft 72. The cylindrical shaft includes a center portionand two opposed end portions. A driving gear assembly 74 is fixedlymounted to the center portion of the cylindrical shaft 72, and drivengears 76, 78 are fixedly mounted to the end portions of the shaft. Thedriving gear assembly 74 is configured to engage the main digger chain40 and transmit force to the auxiliary digger chains 46, 48 which areconfigured to engage the driven gears 76, 78. In the depicted embodimentthe driving gear assembly includes two ring gears connected to a spacerarrangement, and each driven gear includes a ring gear attached to aspacer. In the depicted embodiment the ring gears include the samediameter and number of teeth. It should be appreciated that inalternative embodiments, the bearing assembly 70 can include a differentconfiguration. In the depicted embodiment the space between the drivengear 76, 78 can be adjusted via spacer that enable the driven gears toeither be mounted closer together or further apart. The driven gears aremounted further apart when the auxiliary booms are spaced away from themain boom.

Referring to FIGS. 9 and 10, the system and method for attaching theauxiliary booms 42, 44 to the main boom 34 is described in greaterdetail. In the depicted embodiment the system includes mounting plates80 that are attached to the side of the main boom 34. The mountingplates are configured to be aligned and engaged with structural featuresconnected to the auxiliary booms 42, 44 (e.g., post, bolts, pins,apertures). In the depicted embodiment plates 80 are configured so thatthe spaces between the main boom 34 and auxiliary booms 42, 44 areadjustable. Spacing the auxiliary booms 42, 44 further from the mainboom 34 enables wider digger chains to be mounted to the auxiliary booms42, 44 or enable the same width digger chains to cooperatively dig awider trench with larger spaces between the chains. The plates 80 can beattached to the auxiliary booms via bolts which are received inapertures on the plates 80. The depicted embodiment includes twomounting plates 80 that engagement plates 82-85 on the auxiliary booms42, 44. In the depicted embodiment, the mounting plates 80 include apair of horizontally arranged shear stops that slidably engage a matchset of shear stops on engagement plates 82-85. It should be appreciatedthat many other configurations are also possible. The method ofconnecting the auxiliary booms includes the step of aligning structuralfeatures of the side boom (auxiliary booms) with structural features ofthe main boom; for example, aligning posts on the auxiliary booms 42, 44with the apertures on the mounting plates 80 of the main boom 34.

Referring to FIGS. 12 and 13, the system and method for connecting theauxiliary digger chains 46, 48 to the auxiliary booms 42, 44 isdescribed. In the depicted embodiment the digger chains 46, 48 arepositioned around the auxiliary boom 42, 44 such that they engage thedriven gear 76, 78 and the idler gear 62, 63. The idler gear 62, 63 isconfigured to be adjusted to apply tension to the digger chains 46, 48.In the depicted embodiment the idler gear 62, 63 is mounted to theauxiliary boom via a tension mechanism 90 that allows the idler gear 62,63 to take up slack in the digger chains 46, 48. The idler gear isconnected to a mounting arm 92. The connecting arm 92 is fixed in thevertical direction relative to the auxiliary booms 42, 44, but free toslide in the horizontal direction (direction parallel to the length ofthe booms). A cylinder 94 (e.g., a hydraulic cylinder) or spring ispositioned and configured to normally bias the connecting arm 92 in theproximal direction (i.e., in an outward direction towards the chassis12). In the depicted embodiment one end of the cylinder 94 engages theconnecting arm, and the other end of the cylinder engages a stop blockmechanism 96. In the depicted embodiment the cylinder and stop blockmechanism are used to apply tension to the chain while the bolts 98 aretightened. In some embodiment, the pressure in the cylinder is releasedafter the bolts 98 are tightened. It should be appreciated that manyother alternative tension mechanisms are also possible.

The above specification, examples, and data provide a completedescription of the manufacture and use of the composition of theinvention. Since many embodiments of the invention can be made withoutdeparting from the spirit and scope of the invention, the inventionresides in the claims hereinafter appended.

1. A trencher comprising: a chassis including a first side, second side,first end, and second end; a pair of spaced apart trencher tracks ateach side of the chassis; a main boom positioned between the trenchertracks, the main boom including a first end and second end, wherein thefirst end of the boom is connected to the second end of the chassis; amain digger chain positioned to rotate over the main boom; a firstauxiliary digger chain positioned adjacent a first side of the maindigger chain; a second auxiliary digger chain positioned adjacent asecond side of the main digger chain; wherein the first and secondauxiliary digger chains are driven by the main digger chain.
 2. Thetrencher of claim 1, wherein the second end of the main boom includes adrive shaft configured to receive torque from the main digger chain andtransfer torque to the first and second auxiliary digger chains.
 3. Thetrencher of claim 2, wherein the first and second auxiliary diggerchains are configured and arranged so that cutting surfaces on the lowerhalf of the digger chains are generally aligned with the cutting surfaceof the lower portion of the main digger chain.
 4. The trencher of claim3, wherein the first and second auxiliary digger chains are configuredand arranged such that lower cutting surfaces on the upper portions ofthe digger chains are retracted relative to the adjacent cutting surfaceof the main digger chain.
 5. The trencher of claim 1, further comprisinga first auxiliary boom for supporting the first auxiliary digger chain,the first auxiliary boom being connected to the main boom via a sidemounting plate.
 6. The trencher of claim 1, wherein the main diggerchain includes teeth arranged in two rows that are each angled withrespect to an edge of the digger chain.
 7. The trencher of claim 1,wherein the first and second auxiliary digger chains include teetharranged in rows that are at an angle with respect to the edges of theauxiliary digger chains.
 8. The trencher of claim 1, wherein the firstand second auxiliary digger chains include two or less teeth per plate.9. The trencher of claim 1, wherein the first and second auxiliarydigger chains include dirt drags that overlap adjacent plates.
 10. Atrencher attachment comprising: an auxiliary boom configured to bemounted to the mounting plate, the auxiliary boom configured to supportan auxiliary digger chain; a drive axis configured to be attached to amain boom of a trencher, the drive axis including center gears forengaging a main digger chain and side gears for engaging an auxiliarydigger chain; and a first mounting plate configured to be attached tointerface between the main boom of a trencher and the auxiliary boomsuch that the auxiliary boom is aligned with the side gear for engagingthe auxiliary digger chain.
 11. The trencher attachment of claim 10,wherein the mounting plate is attached to the main boom and includesapertures for receiving bolts that extend from the auxiliary boom. 12.The trencher attachment of claim 10, further comprising an idler gear onan end of the auxiliary boom, wherein the idler gear is configured andarranged on the auxiliary boom to apply tension on an auxiliary diggerchain.
 13. The trencher attachment of claim 12, further comprising atensioning mechanism including a plurality of bolts and a hydrauliccylinder.
 14. The trencher attachment of claim 10, wherein the auxiliaryboom is modular in that the length of the auxiliary boom can be adjustedby removing or adding support sections between the end portions of theauxiliary boom.
 15. A method of trenching comprising: connecting a driveshaft to a distal end of a main boom; connecting an auxiliary boom to aside of the main boom such that a portion of the drive shaft extendsacross a portion of the auxiliary boom; connecting a main digger chainto the main boom such that the main digger chain drives the drive shaft;and connecting an auxiliary digger chain to the auxiliary boom such thatthe drive shaft drives the auxiliary digger chain.
 16. The method ofclaim 15, wherein the proximal portions of the auxiliary boom include apivot for engaging the auxiliary digger chain, and wherein the axis ofthe pivot is positioned closer to an upper cutting surface of the maindigger chain than a lower cutting surface.
 17. The method of claim 16,wherein the upper cutting surface of the auxiliary boom is parallel tothe upper cutting surface of the main digger chain.
 18. The method ofclaim 16, wherein the proximal end of the auxiliary boom has a curvedprofile that gradually guides the auxiliary digger chain away from thelower cutting surface of the main digger chain.
 19. The method of claim16, wherein the radius of curvature is greater than the distance betweenan upper and a lower cutting surface of the main digger chain.
 20. Themethod of claim 17, wherein the teeth on the auxiliary digger chain areconfigured and arranged to direct cut debris into the path of the maindigger chain.